1package eu.siacs.conversations.crypto;
  2
  3import android.util.Log;
  4
  5import net.java.otr4j.OtrEngineHost;
  6import net.java.otr4j.OtrException;
  7import net.java.otr4j.OtrPolicy;
  8import net.java.otr4j.OtrPolicyImpl;
  9import net.java.otr4j.crypto.OtrCryptoEngineImpl;
 10import net.java.otr4j.crypto.OtrCryptoException;
 11import net.java.otr4j.session.FragmenterInstructions;
 12import net.java.otr4j.session.InstanceTag;
 13import net.java.otr4j.session.SessionID;
 14
 15import org.json.JSONException;
 16import org.json.JSONObject;
 17
 18import java.math.BigInteger;
 19import java.security.KeyFactory;
 20import java.security.KeyPair;
 21import java.security.KeyPairGenerator;
 22import java.security.NoSuchAlgorithmException;
 23import java.security.PrivateKey;
 24import java.security.PublicKey;
 25import java.security.spec.DSAPrivateKeySpec;
 26import java.security.spec.DSAPublicKeySpec;
 27import java.security.spec.InvalidKeySpecException;
 28
 29import eu.siacs.conversations.Config;
 30import eu.siacs.conversations.entities.Account;
 31import eu.siacs.conversations.entities.Conversation;
 32import eu.siacs.conversations.generator.MessageGenerator;
 33import eu.siacs.conversations.services.XmppConnectionService;
 34import eu.siacs.conversations.xmpp.chatstate.ChatState;
 35import eu.siacs.conversations.xmpp.jid.InvalidJidException;
 36import eu.siacs.conversations.xmpp.jid.Jid;
 37import eu.siacs.conversations.xmpp.stanzas.MessagePacket;
 38
 39public class OtrService extends OtrCryptoEngineImpl implements OtrEngineHost {
 40
 41	private Account account;
 42	private OtrPolicy otrPolicy;
 43	private KeyPair keyPair;
 44	private XmppConnectionService mXmppConnectionService;
 45
 46	public OtrService(XmppConnectionService service, Account account) {
 47		this.account = account;
 48		this.otrPolicy = new OtrPolicyImpl();
 49		this.otrPolicy.setAllowV1(false);
 50		this.otrPolicy.setAllowV2(true);
 51		this.otrPolicy.setAllowV3(true);
 52		this.keyPair = loadKey(account.getKeys());
 53		this.mXmppConnectionService = service;
 54	}
 55
 56	private KeyPair loadKey(final JSONObject keys) {
 57		if (keys == null) {
 58			return null;
 59		}
 60		synchronized (keys) {
 61			try {
 62				BigInteger x = new BigInteger(keys.getString("otr_x"), 16);
 63				BigInteger y = new BigInteger(keys.getString("otr_y"), 16);
 64				BigInteger p = new BigInteger(keys.getString("otr_p"), 16);
 65				BigInteger q = new BigInteger(keys.getString("otr_q"), 16);
 66				BigInteger g = new BigInteger(keys.getString("otr_g"), 16);
 67				KeyFactory keyFactory = KeyFactory.getInstance("DSA");
 68				DSAPublicKeySpec pubKeySpec = new DSAPublicKeySpec(y, p, q, g);
 69				DSAPrivateKeySpec privateKeySpec = new DSAPrivateKeySpec(x, p, q, g);
 70				PublicKey publicKey = keyFactory.generatePublic(pubKeySpec);
 71				PrivateKey privateKey = keyFactory.generatePrivate(privateKeySpec);
 72				return new KeyPair(publicKey, privateKey);
 73			} catch (JSONException e) {
 74				return null;
 75			} catch (NoSuchAlgorithmException e) {
 76				return null;
 77			} catch (InvalidKeySpecException e) {
 78				return null;
 79			}
 80		}
 81	}
 82
 83	private void saveKey() {
 84		PublicKey publicKey = keyPair.getPublic();
 85		PrivateKey privateKey = keyPair.getPrivate();
 86		KeyFactory keyFactory;
 87		try {
 88			keyFactory = KeyFactory.getInstance("DSA");
 89			DSAPrivateKeySpec privateKeySpec = keyFactory.getKeySpec(
 90					privateKey, DSAPrivateKeySpec.class);
 91			DSAPublicKeySpec publicKeySpec = keyFactory.getKeySpec(publicKey,
 92					DSAPublicKeySpec.class);
 93			this.account.setKey("otr_x", privateKeySpec.getX().toString(16));
 94			this.account.setKey("otr_g", privateKeySpec.getG().toString(16));
 95			this.account.setKey("otr_p", privateKeySpec.getP().toString(16));
 96			this.account.setKey("otr_q", privateKeySpec.getQ().toString(16));
 97			this.account.setKey("otr_y", publicKeySpec.getY().toString(16));
 98		} catch (final NoSuchAlgorithmException | InvalidKeySpecException e) {
 99			e.printStackTrace();
100		}
101
102    }
103
104	@Override
105	public void askForSecret(SessionID id, InstanceTag instanceTag, String question) {
106		try {
107			final Jid jid = Jid.fromSessionID(id);
108			Conversation conversation = this.mXmppConnectionService.find(this.account,jid);
109			if (conversation!=null) {
110				conversation.smp().hint = question;
111				conversation.smp().status = Conversation.Smp.STATUS_CONTACT_REQUESTED;
112				mXmppConnectionService.updateConversationUi();
113			}
114		} catch (InvalidJidException e) {
115			Log.d(Config.LOGTAG,account.getJid().toBareJid()+": smp in invalid session "+id.toString());
116		}
117	}
118
119	@Override
120	public void finishedSessionMessage(SessionID arg0, String arg1)
121			throws OtrException {
122
123	}
124
125	@Override
126	public String getFallbackMessage(SessionID arg0) {
127		return MessageGenerator.OTR_FALLBACK_MESSAGE;
128	}
129
130	@Override
131	public byte[] getLocalFingerprintRaw(SessionID arg0) {
132		try {
133			return getFingerprintRaw(getPublicKey());
134		} catch (OtrCryptoException e) {
135			return null;
136		}
137	}
138
139	public PublicKey getPublicKey() {
140		if (this.keyPair == null) {
141			return null;
142		}
143		return this.keyPair.getPublic();
144	}
145
146	@Override
147	public KeyPair getLocalKeyPair(SessionID arg0) throws OtrException {
148		if (this.keyPair == null) {
149			KeyPairGenerator kg;
150			try {
151				kg = KeyPairGenerator.getInstance("DSA");
152				this.keyPair = kg.genKeyPair();
153				this.saveKey();
154				mXmppConnectionService.databaseBackend.updateAccount(account);
155			} catch (NoSuchAlgorithmException e) {
156				Log.d(Config.LOGTAG,
157						"error generating key pair " + e.getMessage());
158			}
159		}
160		return this.keyPair;
161	}
162
163	@Override
164	public String getReplyForUnreadableMessage(SessionID arg0) {
165		// TODO Auto-generated method stub
166		return null;
167	}
168
169	@Override
170	public OtrPolicy getSessionPolicy(SessionID arg0) {
171		return otrPolicy;
172	}
173
174	@Override
175	public void injectMessage(SessionID session, String body)
176			throws OtrException {
177		MessagePacket packet = new MessagePacket();
178		packet.setFrom(account.getJid());
179		if (session.getUserID().isEmpty()) {
180			packet.setAttribute("to", session.getAccountID());
181		} else {
182			packet.setAttribute("to", session.getAccountID() + "/" + session.getUserID());
183		}
184		packet.setBody(body);
185		MessageGenerator.addMessageHints(packet);
186		try {
187			Jid jid = Jid.fromSessionID(session);
188			Conversation conversation = mXmppConnectionService.find(account,jid);
189			if (conversation != null && conversation.setOutgoingChatState(Config.DEFAULT_CHATSTATE)) {
190				if (mXmppConnectionService.sendChatStates()) {
191					packet.addChild(ChatState.toElement(conversation.getOutgoingChatState()));
192				}
193			}
194		} catch (final InvalidJidException ignored) {
195
196		}
197		packet.setType(MessagePacket.TYPE_CHAT);
198		packet.addChild("encryption","urn:xmpp:eme:0")
199				.setAttribute("namespace","urn:xmpp:otr:0");
200		account.getXmppConnection().sendMessagePacket(packet);
201	}
202
203	@Override
204	public void messageFromAnotherInstanceReceived(SessionID session) {
205		sendOtrErrorMessage(session, "Message from another OTR-instance received");
206	}
207
208	@Override
209	public void multipleInstancesDetected(SessionID arg0) {
210		// TODO Auto-generated method stub
211
212	}
213
214	@Override
215	public void requireEncryptedMessage(SessionID arg0, String arg1)
216			throws OtrException {
217		// TODO Auto-generated method stub
218
219	}
220
221	@Override
222	public void showError(SessionID arg0, String arg1) throws OtrException {
223		Log.d(Config.LOGTAG,"show error");
224	}
225
226	@Override
227	public void smpAborted(SessionID id) throws OtrException {
228		setSmpStatus(id, Conversation.Smp.STATUS_NONE);
229	}
230
231	private void setSmpStatus(SessionID id, int status) {
232		try {
233			final Jid jid = Jid.fromSessionID(id);
234			Conversation conversation = this.mXmppConnectionService.find(this.account,jid);
235			if (conversation!=null) {
236				conversation.smp().status = status;
237				mXmppConnectionService.updateConversationUi();
238			}
239		} catch (final InvalidJidException ignored) {
240
241		}
242	}
243
244	@Override
245	public void smpError(SessionID id, int arg1, boolean arg2)
246			throws OtrException {
247		setSmpStatus(id, Conversation.Smp.STATUS_NONE);
248	}
249
250	@Override
251	public void unencryptedMessageReceived(SessionID arg0, String arg1)
252			throws OtrException {
253		throw new OtrException(new Exception("unencrypted message received"));
254	}
255
256	@Override
257	public void unreadableMessageReceived(SessionID session) throws OtrException {
258		Log.d(Config.LOGTAG,"unreadable message received");
259		sendOtrErrorMessage(session, "You sent me an unreadable OTR-encrypted message");
260	}
261
262	public void sendOtrErrorMessage(SessionID session, String errorText) {
263		try {
264			Jid jid = Jid.fromSessionID(session);
265			Conversation conversation = mXmppConnectionService.find(account, jid);
266			String id = conversation == null ? null : conversation.getLastReceivedOtrMessageId();
267			if (id != null) {
268				MessagePacket packet = mXmppConnectionService.getMessageGenerator()
269						.generateOtrError(jid, id, errorText);
270				packet.setFrom(account.getJid());
271				mXmppConnectionService.sendMessagePacket(account,packet);
272				Log.d(Config.LOGTAG,packet.toString());
273				Log.d(Config.LOGTAG,account.getJid().toBareJid().toString()
274						+": unreadable OTR message in "+conversation.getName());
275			}
276		} catch (InvalidJidException e) {
277			return;
278		}
279	}
280
281	@Override
282	public void unverify(SessionID id, String arg1) {
283		setSmpStatus(id, Conversation.Smp.STATUS_FAILED);
284	}
285
286	@Override
287	public void verify(SessionID id, String fingerprint, boolean approved) {
288		Log.d(Config.LOGTAG,"OtrService.verify("+id.toString()+","+fingerprint+","+String.valueOf(approved)+")");
289		try {
290			final Jid jid = Jid.fromSessionID(id);
291			Conversation conversation = this.mXmppConnectionService.find(this.account,jid);
292			if (conversation!=null) {
293				if (approved) {
294					conversation.getContact().addOtrFingerprint(fingerprint);
295				}
296				conversation.smp().hint = null;
297				conversation.smp().status = Conversation.Smp.STATUS_VERIFIED;
298				mXmppConnectionService.updateConversationUi();
299				mXmppConnectionService.syncRosterToDisk(conversation.getAccount());
300			}
301		} catch (final InvalidJidException ignored) {
302		}
303	}
304
305	@Override
306	public FragmenterInstructions getFragmenterInstructions(SessionID sessionID) {
307		return null;
308	}
309
310}